Bromocriptine, a sympathic dopamine D2 agonist with serotonin antagonist activities, has been demonstrated to inhibit the seasonal development of obesity-related glucose intolerance in hamsters; in part by resetting circadian hypothalamic neural activities known to regulate this annual cycle. Since Ergoset (ERG), a new quick release formulation of bromocriptine, has been demonstrated to improve glycemic control in patients with Type 2 diabetes, the present study was initiated in patients to evaluate the effect of ERG on fasting and postprandial levels of various hormones, as well as glucose and lipid levels in 12 obese, hyperinsulinemic, non-diabetic women.